The first is on CNN.com: "Perimenopause: Hormone ups and downs can last years." A tidbit:
Perimenopause can begin as long as 10 years earlier [than menopause], but women often fail to connect irksome symptoms to the beginning of "the change." For example, an important first clue may be sleep difficulties, which affect about 30 percent of women. Other symptoms may be more familiar, such as intense irritability, decreased libido and mood fluctuations, often for women who've never experienced moodiness before.
The second article is from Harvard Women's Health Watch: "Perimenopause: Rocky road to menopause." As you might imagine, coming from Harvard Medical School, this article goes into more scientific detail but is quite comprehensible and very valuable. Here's a sample:
[P]erimenopause (peri, Greek for “around” or “near,” + menopause) is an extended transitional state.
. . . .
Perimenopause varies greatly from one woman to the next. The average duration is three to four years, although it can last just a few months or extend as long as a decade. Some women feel buffeted by hot flashes and wiped out by heavy periods; many have no bothersome symptoms. Periods may end more or less abruptly for some, while others may menstruate erratically for years.
Men would do well to be aware of perimenopause. The next post will be about "male menopause." Ladies, you should be aware of that too.